This invention relates to a screen-printing apparatus.
Heretofore, a screen-printing apparatus comprises a mask and a mask support frame, a squeegee device, a printing table for supporting a material to be printed, and a camera device for imaging a position confirmation mark on the material to be printed by means of a camera so as to confirm a position of the material.
In the screen-printing apparatus, the material to be printed, which is disposed on the printing table, is positioned with respect to the mask before printing the material by means of the squeegee. This positioning operation is carried out by imaging a position confirmation mark on the material to be printed by means of a camera in the camera device to confirm a position of the material, and displacing the printing table in a right-left direction and a front-rear direction, and simultaneously rotating the squeegee device in a horizontal plane.
However, in the case where the printing table is moved to adjust the position of it, it involves a problem to rotate the printing table in a horizontal plane and it is difficult to achieve a high accuracy. In fact, there is an error more than 50 xcexcm (microns) in the positioning operation and a misalignment will occur in a fine pattern printing. Consequently, it is impossible to obtain a high quality product.
Also, since the printing table is moved in the prior art, only a single material to be printed must be set on the printing table at every printing step. This will lower a working efficiency.
Accordingly, an object of the present invention is to provide a screen-printing apparatus in which a mask is moved to adjust a relative position between a mask and a material to be printed, thereby enhancing accuracy and making possible an application to not only a single material but also an elongate film like material to be printed, since the printing table is fixed.
In order to achieve the above object, a screen-printing apparatus of the present invention comprising a mask and a mask support frame, a squeegee device, a printing table for supporting a material to be printed, and a camera device for imaging a position confirmation mark on the material by means of a camera to confirm a position of the material, in which the printing table is fixed at a given position, the mask is displaced in a right-left direction and a front-rear direction, and is rotated in a horizontal plane in accordance with a position confirmation signal from the camera device so as to accord the positions of the mask and the material to be printed, further the mask, the mask support frame, and the squeegee device are moved up and down together at a predetermined timing at every printing step.
The material to be printed is a roll of an elongate film, drawn out from a bobbin and printed on the printing table in order. Accordingly, the present invention can greatly improve a working efficiency, since a step of setting a single material to be printed on a printing table at every printing step in the prior art can be omitted in the present invention. Also, the material to be printed is made of a transparent or semitransparent film and the camera device is arranged so that the camera is directed vertically in the printing table. Consequently, it is possible to speed up a step of confirming a position by a camera.